Lens modeling results on the HST/WFC3 (top) and ALMA data (bottom). Left panels: original lens plane. The tiny white ellipse in the bottom left corner of the ALMA original lens plane is the final image-restored beam. The best-fit lens plane is shown in the central panel of the left column; the panel on its right shows the residuals. Right panels: reconstructed source plane on Voronoi tassels. Contours are from 3σ level to the maximum S/N with steps of 3 (ALMA) and 5 (HST). White and red curves are the lens caustics and critics, respectively, on the lens plane and on the source plane; the angular and physical scales are reported in white in the bottom right corner of every panel.